The invention relates to slow-release air freshener compositions comprising a perfume intimately dispersed in a unique combination of three thermoplastic carriers in specified proportions.
It is known to incorporate an odorant in a polymer carrier such as polyvinyl chloride. Exposure of the resulting composition to the air over a prolonged period of time may result in the emission of the odorant at the surface of the composition. Compositions of this kind are designated in this application as slow-release air freshener compositions.
In order to be effective and practical as a slow-release air freshener, the composition should generally meet the following two criteria. Firstly, it should be of such quality that when allowing the odorant to evaporate into a space such as a room through the surface of the carrier, a concentration of odorant can be obtained in that space which is sufficiently high to achieve odor control in the room. Secondly, for practical and aesthetic reasons it is desirable that the composition, while meeting the first criterion, also has a reasonable high compactness, which can be achieved if the diffusivity of the odorant in the polymer carrier is relatively high.
The known composition comprising polyvinyl chloride and an odorant generally does not meet these essential requirements, but it has surprisingly been found that, if a combination of three certain thermoplastic carriers are used, a very suitable slow-release air freshener composition can be obtained.